1. Field of the Invention
The invention relates to a method and apparatus for converting heat energy into work energy and also for pumping heat energy from a low temperature level to a high temperature level. A characteristic feature of the invention is in the use of a working medium which is subjected to a cylcic operation, each comprises of a melting step and a solidification step operated under two pressure levels and at two temperature levels.
2. Brief Description of the Prior Art
In a conventional external heat engine, a working medium, such as water, is generally subjected to a high pressure vaporization operation to absorb heat at a high temperature level, resulting high pressure vapor is depressurized through a turbine to produce work, the exhaust vapor from the turbine is condensed at a low pressure to reject heat at a low temperature level, and finally the condensate is returned to the high pressure vaporization operation described.
In a conventional heat pump, a refrigerator or an air conditioner, a working medium, such as ammonia and Freon, is vaporized at a low temperature level, the low pressure medium vapor is then compressed to a high pressure, the resulting pressurized medium vapor is condensed under the high pressure to release heat at a high temperature level and finally the condensed medium is returned to the low pressure vaporization operation. The efficiencies of these conventional heat engines and heat pumps are generally less than 70% of the theoretical thermodynamic efficiencies.